Upon a POR, the fuel gauge copies ROM-based configuration defaults to RAM and begins INITIALIZATION mode where essential data is initialized. The occurrence of a POR or a Control() RESET subcommand will set the Flags() [ITPOR] status bit to indicate that RAM has returned to ROM default data. When battery insertion is detected, a series of initialization activities begin including an OCV measurement. In addition, CONTROL_STATUS [QMAX_UP] and [RES_UP] bits are cleared to allow unfiltered learning of Qmax and impedance. Completion of INITIALIZATION mode is indicated by the CONTROL_STATUS [INITCOMP] bit.